A conventional image reader electrically communicated with a POS terminal, i.e., Point of Sales terminal, optically captures an image showing a code symbol on a label attached to a commodity or an object image partly and/or totally showing a commodity through an opening provided to a housing of the image reader. The image reader decodes the captured image to generate code information relating to the code symbol, e.g., a commodity code, or extracts feature amount from the captured object image. The code symbol image or the object image is captured by an image detector, e.g., CCD sensor (Charge Coupled Device sensor), provided in the image reader.
The opening in the image reader is covered with a transparent flat plate having permeability, e.g., glass, resin and so on, to prevent foreign matters or dust from being stuck to the image detector.
The image reader includes a lighting device to illuminate an image reading area in which a code symbol on a label or an object is brought to capture the image thereof. An imaging area is allocated for the image detector to receive light reflected by the code symbol or the object. A part of the imaging area corresponds to the image reading (capturing) area. The lighting device includes an LED (Light Emitting Diode). A part of Light, emitted by the lighting device, which is reflected by the transparent plate, becomes a stray light. To prevent the stray light from arriving at the image detector, the lighting device is placed outside of an equivalent imaging area to illuminate the imaging area allocated to the image detector.